Brian's not the first one to tackle this. Finnish eccentric genius M.A.Numminen composed six songs to the book "Tractatus Logico-Philosophicus" by philosopher Ludwig Wittgenstein in 1966 (listen to A Proposition Is [MP3]). And these works have alas (sadly for my listeners), spawned my own adventures into the field: Kenny G Sings Wittgenstein (MP3) Part 1 | Part 2. Ouch.

M. A. Nuuminen studied philosophy at the University of Helsinki, said to me one of the professors there. This is the probable origin of the idea of singing the Tractactus. I indeed has this CD at my hands at Helsinki. Very sorry for not have bought it. Very funny to listen to Wittgenstein sang in this way.